Brian & Jesus.
I just went through a period where I read all of the Sharpe novels by Bernard Cornwell. And then I read some Nero Wolfe novels by Rex Stout.
And then I imagined how much Richard Sharpe and Archie Goodwin would hate, hate, hate each other. If they spent enough time together, they *might * come to respect one another as fellow men-of-action … but they wouldn’t. Within about ten minutes, Archie would verbally run rings around Sharpe, and then Sharpe would disembowel Archie.
It would be cool.
I just choke on coffee.
Kinky Friedman and his posse and Andrew Vachss’s Burke and his posse. Image a conversation between Mama and Ratso.
Spoilers for the second Pirates movie, Dead Man’s Chest:
If Sparrow gets those letters of marque he’s aiming for, he and Aubrey could end up colleagues, in an odd sort of way.
Good topic, I’ll be thinking about this all day.
Horatio Hornblower & Pilot-Major John Blackthorne
From two of my favorite authors, Lawrence Block & Lee Child-
Matt Scudder & Jack Reacher and they can swing by and pick up Travis McGee
The Piker from Snatch ( Brad Pitt’s character) and Captain Jack Sparrow. The incomprehensiblity Factor of conversations would be fun!
Mystique, and Leonard Zelig.
Sam Vimes and Inspector Clouseau. I’ll bring the popcorn and beer if someone else can provide lawn chairs.
The Smurfs and the Nac Mac Feegle. Can you imagine the carnage?
Leonard of Quirm and MacGyver. Again, can you imagine the carnage?
Bernard Marx and Winston Smith.
Better: Doctor Who and Doctor Emmett Lathrop “Doc” Brown (Back to the future)
Bellatrix Lestrange and Ferdinand, Duke of Calabria (The Duchess of Malfi). Match made in hell, that one.
Dunno if any of these have been callled, I’m afraid I only skimmed the thread…
Doctor Who and Bill and Ted
Captain James T. Kirk and Han Solo
Horatio Hornblower and Honor Harrington
Constable Benton Fraser, RCMP and Detective Logan, NYPD
Walker, Texas Ranger and Lone Wolf McQuade
Tyler Durden and Scorpius
Commander John Chriton and Colonel Cameron Mitchell
Toranaga and the Patrician.
Worf and Teal’c. As much as I like Worf, the directing made him look like a chump too often. Teal’c kicks ass all over the place though.
[sub]OK, I guess I have to officially admit that Stargate SG-1 isn’t as bad as I thought. Hmph. I dunno about Atlantis though, that woman’s nose creeps me out.[/sub]
It almost happened in Who Framed Roger Rabbit.
Worf would be more of a badass if they’d only give him a fedora! 
Captain Jean-Luc Picard and Colonel Steven Caldwell . May the best bald starship commander win.
She Hulk and Tarl Cabot ( the main protagonist from those repellant Gor novels ).
Gandalf and Belgarath.
Elric of Melniboné and the entire cast of Alice in Wonderland. I’m not sure what would happen, but it would be . . . odd.
Heh.
That’s cruel. Why would you want to send dear Jenny to prison? Because you KNOW she’d kill him. Or at least cripple him.
don Juan from Journey to Ixtlan and Gunny Hartman from Full Metal Jacket.